floppy: use blk_mq_alloc_disk and blk_cleanup_disk

Use blk_mq_alloc_disk and blk_cleanup_disk to simplify the gendisk and
request_queue allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Link: https://lore.kernel.org/r/20210602065345.355274-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/floppy.c

@@ -4491,23 +4491,15 @@ static bool floppy_available(int drive)
 static int floppy_alloc_disk(unsigned int drive, unsigned int type)
 {
 	struct gendisk *disk;
-	int err;
-
-	disk = alloc_disk(1);
-	if (!disk)
-		return -ENOMEM;
 
-	disk->queue = blk_mq_init_queue(&tag_sets[drive]);
-	if (IS_ERR(disk->queue)) {
-		err = PTR_ERR(disk->queue);
-		disk->queue = NULL;
-		put_disk(disk);
-		return err;
-	}
+	disk = blk_mq_alloc_disk(&tag_sets[drive], NULL);
+	if (IS_ERR(disk))
+		return PTR_ERR(disk);
 
 	blk_queue_max_hw_sectors(disk->queue, 64);
 	disk->major = FLOPPY_MAJOR;
 	disk->first_minor = TOMINOR(drive) | (type << 2);
+	disk->minors = 1;
 	disk->fops = &floppy_fops;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	if (type)
@@ -4727,10 +4719,8 @@ static int __init do_floppy_init(void)
 		if (!disks[drive][0])
 			break;
 		del_timer_sync(&motor_off_timer[drive]);
-		blk_cleanup_queue(disks[drive][0]->queue);
-		disks[drive][0]->queue = NULL;
+		blk_cleanup_disk(disks[drive][0]);
 		blk_mq_free_tag_set(&tag_sets[drive]);
-		put_disk(disks[drive][0]);
 	}
 	return err;
 }